The Japanese author of a controversial stem cell paper
has agreed to retract
one of her two publications in Nature. Haruko Obokata reportedly has told co-authors on the paper on stimulus-triggered acquisition of pluripotency (STAP) cells that she was prepared to retract it. In principle all co-authors must agree to a retraction. However, she still refuses to retract the second of the two papers published in January.

Most of the other co-authors have agreed to the retraction, but not the American co-author, Charles Vacanti, of Brigham and Women's Hospital in Boston.

The paper which Obokata refuses to retract is the main one, in which it was claimed that putting cells under stress by bathing them in acid of subjecting them to physical pressure leads to the creation of pluripotent stem cells. The other paper claims that these cells can produce placental tissue.

"To Obokata, the paper that made clear the existence of STAP is the important one. The other [which she has agreed to retract] is nothing more than an extension," says her lawyer.

The papers came under fire after several researchers were unable to replicate her findings and manipulated and duplicated images were found in them. The RIKEN research institute found her guilty of scientific misconduct, although Dr Obokata insists that her mistake were the result of inexperience, not fraud.